1. Technical Field
The present invention generally relates to detecting roadwheel misalignment as a vehicle is being operated or driven, and more particularly relates to a vehicle integrated wheel alignment monitoring and alignment system.
2. Description of Related Art
In the automotive and trucking industry, it is known that roadwheel misalignment decreases safety through poor vehicle handling, especially on wet or uneven road surfaces; creates driver fatigue when driving long distances; increases tire tread wear and vehicle fuel consumption, which increases vehicle operating cost. A long-standing problem has existed with prior devices designed to detect roadwheel misalignment during vehicle motion. In general, prior devices detect misalignment of a vehicle's roadwheel by detecting either displacement or torque experienced by a steering or roadwheel component. However, a problem arises from inherent displacement of steering and roadwheel components during vehicle motion due to loads or forces experienced by a tire, steering component, suspension component, and drive axle. Such displacement can interfere with identifying misalignment by creating a false appearance of roadwheel misalignment even though the roadwheels are properly aligned. This is especially true if the inherent displacement causes a prolonged self steer event, where the vehicle's driver has to apply a counter steer input or torque on the steering wheel when driving in a straight line. A self steer condition can be associated with: (i) a bump steer or roll steer effect caused by the suspension's geometry; or (ii) a deflection steer caused by twisting of rubber suspension bushings during vehicle acceleration and braking; or (iii) a steering pull during straight line driving caused by tire ply steer, mismatched tires, low tire pressure, memory steer, engine torque steer, load distribution, or road crown. Therefore, based on the foregoing, there is still a clear need in this field for a vehicle integrated wheel alignment monitoring system.